Locking gas cap with torque override feature

ABSTRACT

A locking gas cap for a threaded filler neck having a sealing lip extending peripherally about its axis, the cap comprising a closure member threaded to engage and close the filler neck, a gasket on the closure member for engaging and sealing against the lip, an outer shell providing a hand grip secured to the closure member for rotation thereon, a key-operated lock and at least one lock-actuable bolt connected to the shell for rotation therewith. A race is disposed for rotation in the shell, and a driving connection is provided between the race and the closure member which is torque limited in the direction which advances the closure member on the filler neck and positive in the cap removal direction. A spring is provided for yieldably urging the bolt into engagement with the race. The spring cooperates with a plurality of engaging pockets in the race to provide a positive driving connection between the shell and race in the direction which advances the closure onto the filler neck. When the lock is not in a cap removal position and the shell is rotated in the cap removal direction, the bolt cams out of the pockets against the urging of the spring, allowing the shell to turn with respect to the race to prevent cap removal. When the lock is in its cap removal position, it blocks motion of the bolt out of the pockets to lock the shell to the race.

This application is a division of application Ser. No. 735,252, filedOct. 29, 1976, now U.S. Pat. No. 4,107,961 and assigned to the sameassignee as the present invention. Application Ser. No. 735,252 is acontinuation-in-part of application Ser. No. 611,219, filed Sept. 8,1975, now U.S. Pat. No. 4,000,633

The present invention relates to caps for vehicle fuel tanks and moreparticularly to the provision of a threaded cap for a threaded fillerneck, which cap is provided with a key lock to protect the contents ofthe fuel tank as well as a torque-override feature to protect thesealing gasket of the cap and to prevent the cap from being threaded tootightly onto the filler neck. Locking gas caps are, of course, very oldin the art. Most locking gas caps, however, are designed to work withfiller necks which have peripherally extending cam-lock surfaces ratherthan filler necks which are threaded. Such conventional locking gas capsinclude a cylinder lock mechanism for moving a locking member radiallyinto engagement with the cam lock surface to prevent unauthorizedremoval of the cap.

The prior art also includes showings of locking caps, not necessarilyfuel caps, comprising threaded closure members and outer shells withkey-lock means for selectively providing a driving connection betweenthe outer shells and the closure members. In such devices, until the keyis actuated, the outer shell will simply rotate on the closure memberand not disengage the closure member from its closing position. See, forinstance, U.S. Pat. Nos. 2,101,758, 2,070,692 and 2,467,087. The presentinvention involves a considerable improvement over such threaded lockingcaps of the prior art. First of all, the present invention incorporatesa torque-override feature which prevents the closure member of the capfrom being twisted too tightly on the filler neck, thereby damaging thethreads or the gasket which provides a seal between the filler neck andthe closure member. The torque-override feature also prevents tighteningthe cap so tight it is difficult to remove.

While the prior art does have showings of gas caps with torque-overridefeatures, for instance as shown in the Dawson Friend U.S. Pat. No.3,820,680, the present invention constitutes a significant improvementbecause of the manner in which the torque-override feature isincorporated with the locking feature. Particularly, in the cap of thepresent invention, a race is provided in the outer shell for rotationabout the coinciding axes of the outer shell and closure member, thisrace serving as an important part of the locking feature as well as animportant part of the torque-override feature.

According to the present invention, a locking gas cap includes a racedisposed for rotation in an outer shell which provides the hand grip forthe cap. Means are provided for drivingly connecting the race and theclosure member for rotation together about the coinciding axes of thecap and filler neck, the connecting means being torque-limited in thedirection which advances the closure member on the filler neck andpositive in the opposite direction. The outer shell carries lockingmeans including a lock-actuable bolt. The cap further includes means foryieldably urging the bolt into engagement with the race, the raceincluding engaging means cooperating with the bolt drivingly to connectthe shell to the race when the shell is turned in a direction to advancethe cap on the filler neck and to provide slipping or ratchetingrotation of the shell with respect to the race when the shell is turnedin a cap removal direction and the lock is not in a cap removalposition. When the lock is in the cap removal position, the bolt is heldagainst movement out of engagement with the race for removal of the capfrom the filler neck.

The invention may best be understood by referring to the followingdescription and accompanying drawings which illustrate the invention. Inthe drawings:

FIG. 1 is a sectional view of a cap constructed in accordance with thepresent invention;

FIG. 2 is a sectional view taken from FIG. 1 generally along the line2--2;

FIG. 3 is a view similar to FIG. 2 only showing the locking members intheir radially outer positions engaging the race;

FIG. 4 is a sectional view taken along the line 4--4 in FIG. 1;

FIG. 5 is an enlarged fragmentary sectional view taken from FIG. 1generally along the line 5--5;

FIG. 6 is a partly sectional side elevational view of another capconstructed in accordance with the present invention;

FIG. 7 is a sectional view of the cap of FIG. 6 taken generally alongsection line 7--7 thereof;

FIG. 8 is a sectional view of another cap constructed in accordance withthe present invention;

FIG. 9 is a fragmentary sectional view of the cap of FIG. 8 takengenerally along section line 9--9 thereof; and

FIG. 10 is a fragmentary sectional view of the cap of FIGS. 8-9 takengenerally along section line 10--10 of FIG. 9.

Referring to the drawings, and particularly to FIGS. 1-5, it will beseen that the cap 10 comprises a molded plastic closure member 12 havingan axially inwardly extending shank threaded as indicated at 14 andproviding a pressure-vacuum valve assembly 16 for controlling venting ofthe fuel tank through an opening 18, the valve assembly including avalve cover plate 20 having an opening 21 centrally located therein andbeing secured in place by staked-over portions 20a (FIG. 4). The valveassembly further includes a pressure valve 22 urged to its closingposition by means of a spring 24 and spring plate 26, the pressure valvehaving a central opening 28 therein normally closed by a vacuum valvemember 30 urged to its closing position by a spring 32. Such a valveassembly 16 is now well known in the art and is merely illustrative inthis disclosure. In order to assure that venting occurs through thevalve assembly 16, the closure member 12 carries a sealing ring 38 aboutits shank portion and against its upper, peripherally and radiallyoutwardly extending flange 40. The illustrative flange 40 is providedwith a pair of diametrically opposed, peripherally extending drivefingers or pawls 42 having distal end portions 44. The fingers 42 areintegrally formed on the closure member resiliently to be urgedupwardly. Each finger 42 distal end portion 44 has a best viewed in FIG.5 an inclined wall 46 and an abrupt wall 48.

The cap 10 also comprises an outer shell 50 secured to the closuremember 12 for rotation on the closure member about the axis of the cap10. The illustrative outer shell 50 is formed by an upper shell member52 and lower shell member 54 which provides an axially outwardly facing,radially inwardly extending flange surface 56 for engaging the bottomside of the flange 40, the parts 52, 54 being joined together asindicated at 58. The outer shell 50 is provided with a concentricopening 62 to accommodate the cylinder lock assembly indicated generallyat 63 and four peripherally spaced apart, radially outer pockets 64 forreceiving, respectively, radially outwardly extending tabs 66 formed onthe lock assembly 63 housing 68, only two such pockets 64 and tabs 66being shown. The engagement of the tabs 66 in the pocket 64 secures thelock assembly 63 in the outer shell 50 for rotation therwith relative tothe closure member 12. The illustrative housing 68 is primarily acylindrically formed housing providing a concentric, inner cylindricalshell 70 having an upper portion 72 received in the opening 62 anddefining an internal cylindrical opening 74 for receiving a conventionalcylinder 76 which is secured against axial movement upwardly out of theopening 74 by a locking ring 78.

The housing 68 is also illustratively formed to have an outer annulardepending wall 80 formed to provide, at its distal (lower) edge,radially outwardly extending slots 82 which serve as guide means forlocking members to be described hereinafter. The housing is alsoillustratively formed with transversely extending guide walls 84 forsuch locking members, these walls being best seen in FIGS. 2 and 3.

The illustrative locking members 88, 90 are formed to have interlockingportions 88a, 90a and slots 91 for receiving the axially extending drivepins 92 provided by the cylinder 76. When the cylinder is rotatedclockwise as viewed in FIG. 2, the pins 92 engage the slots 91 to drivethe locking members 88, 90 radially outwardly or to their radially outerpositions shown in FIG. 3, each locking member having a locking bolt orlocking portion 96, 98 guided for movement radially through the slots 82in the wall 80.

The cap 10 comprises also a race 106 which is illustratively an annularmember disposed in the outer shell 50 for rotation relative theretoabout the cap axis. The race 106 provides a plurality of peripherallyspaced apart, radially inwardly facing notches 108 having peripherallyspaced apart walls 110, 112, the wall 110 being an abrupt wall and thewall 112 being a chordally and axially extending inclined wall asillustrated. The locking portions or bolts 96, 98 engage into thesenotches 108 as best seen in FIG. 3. With the locking members 88, 90 inthe positions shown in FIG. 3, rotation of the outer shell 50 and,consequently, the locking members 88, 90 will rotate the race 106 withthe outer shell. The inclined walls 112 aid in directing bolts 96, 98into notches 108.

The race 106 is also formed to provide a plurality of peripherallyspaced apart, downwardly facing pockets 120 having peripherally spacedapart, radially extending faces or walls 122, 124, the wall 122 beingabrupt and the wall 124 being inclined as best seen in FIG. 5. Thedistal end portions 44 of the fingers 42 engage into these pockets 120.Looking at FIG. 5, when the race 106 is moved to the right whichcorresponds to clockwise movement of the cap 10, looking down at the capon the filler neck of the vehicle, the inclined wall 124 will actagainst the incline 46 of the finger 42 to move the finger downwardlyout of engagement with the race 106. This provides the torque-overridefeature of the cap 10 which prevents the cap from being tightened sothat the threads 14 or the sealing ring 38 will not be damaged. Thepockets 120, of course, cooperate with the fingers 42 much in the samemanner as a ratchet and pawl arrangement. When it is desired to removethe cap, assuming that the race 106 is drivingly connected to the outershell 50 by actuation of the locking members 88, 90, the abrupt wall 122of a pocket 120 will engage the abrupt wall 48 of a drive finger 42 tomove the closure member counterclockwise threadedly to disengage thefiller neck. The driving connection, therefore, between the race 106 andclosure member 12 is torque-limited in the direction which advances thethreaded engagement of the cap on the filler neck and positive in theopposite direction to permit removal of the cap when the cylinder lockis actuated drivingly to connect the outer shell 50 to the race 106.

Often, an automobile owner will desire to use his key to project thelocking members 88, 90 radially outwardly so that the cap 10 can beremoved from the filler neck. Then, while the cap 10 is off the fillerneck and, for instance, the tank is being filled, the key may be removedfrom the cylinder 76 leaving the locking members 88, 90 in a retractedposition or radially inner position. It is necessary conventionally tomove the drive pins 92, 94 back to their starting position in order toremove the key from the cylinder 76. In such a case, the outer shell 50is drivingly connected to the race 106 by frictional driving means. Theillustrative frictional driving means includes a spring steel band 140having its proximal end 142 bent radially inwardly and, therefore,connected to the race 106 and its distal end free. The spring 140 iswrapped about an outer diameter 144 of the race 106 radially to expandoutwardly to engage a concentric internal wall 146 of the outer shell50. The spring band 140 extends from this proximal end 142counterclockwise about the wall 144. Thus, when the outer shell 50 isrotated in the clockwise direction, the spring band tends to expand toengage the shell wall 146 to provide a frictional driving connectionwhich is sufficient to move the race 106 to drive the closure member 12onto the filler neck. In fact, the driving torque of the spring band 140is greater than the torque at which the fingers 42 will be cammed out ofengagement with the pockets 120. Additionally, inclined walls 112 ofnotches 108 serve to cam bolts 96, 98 radially inwardly out of notches108 when the outer shell 50 is rotated for advancing closure member 14into the filler neck to close the fuel tank. This protects the lockmechanism and leaves the driving to the spring band 140.

In a second embodiment of the gas cap, illustrated in FIGS. 6-7, thoseelements numbered identically with the elements of FIGS. 1-5 perform thesame or similar functions. In the second embodiment, race 106 provides aplurality of peripherally spaced apart, radially inwardly facing notchesor pockets 108, as in the preceding embodiment. However, theperipherally spaced apart walls 110', 112' in the race 106 of the secondembodiment are reversed. That is, the abrupt, radially and axiallyextending wall 110' in the second embodiment is on the opposite side ofeach pocket 108 from wall 110 in the first embodiment of FIGS. 1 and 5.Thus, wall 112' of each pocket 108 is on the opposite side of the pocketfrom wall 112 of the first embodiment. As before, each wall 112' extendsgenerally along a chord of the circle defining the radially inwardlyfacing surfaces of pockets 108.

The locking bolts 96, 98 are yieldably urged into engagement withpockets 108 by a pair of helical springs 160, 162, respectively. Helicalsprings 160, 162 are disposed in cavities 164, 166, respectively, inlocking members 88, 90. Springs 160, 162 are positioned against theinner side of depending wall 80 of housing 68 in notches 168, 170,respectively, provided therefor. Spring 160 urges against interlockingportion 90a of member 90 to urge the bolt 98 of member 90 outwardly intoengagement with one of pockets 108. Spring 162 urges againstinterlocking portion 88a to urge bolt 96 outwardly into engagement withone of pockets 108.

The slots 91' of locking members 88, 90 in the second embodiment aresomewhat larger than the slots 91 of the first embodiment of FIGS. 1-5.Rotation of the cylinder 76 of the embodiment of FIGS. 6-7 in theclockwise direction, as indicated by the arrows in FIG. 7, positions thedrive pin 92 to lock bolts 96, 98 in their radially extended cap removalpositions. However, due to the size of slots 91', rotation of cylinder76 and movement of drive pins 92 in the counterclockwise direction (tothe positions illustrated in FIG. 7) does not cause bolts 96, 98 to beretracted from engagement with pockets 108. The ends 176, 178 of bolts96, 98, respectively, are shaped to cooperate with walls 110' to providea driving connection between outer shell 50 and race 106 in thedirection (clockwise looking down on the filler neck) to advance closure12 on the filler neck. Springs 160, 162 urge ends 176, 178 outwardlyinto engagement with walls 110'. Walls 112' cooperate with ends 176, 178to cam bolts 96, 98 and their respective locking member 88, 90 radiallyinwardly against the urging of springs 160, 162 to allow outer shell 50to ratchet with respect to race 106 when shell 50 is turned in suchdirection (counterclockwise looking down on the filler neck) to removecap 10 from the filler neck. Radially inward projection of lockingmembers 88, 90 when drive pins 92 are not in the cap removal position isallowed by the ample size of slots 91'.

In a third embodiment of the invention, illustrated in FIGS. 8-10, thoseelements numbered identically with the elements in the embodiments ofFIGS. 1-7 perform the same or similar functions. In the thirdembodiment, as in the second embodiment, helical springs 160, 162 urgelocking members 88, 90 and their respective bolts 96, 98 radiallyoutwardly into pockets 108. In the third embodiment, springs 160, 162are housed in cavities 164', 166' in lock assembly housing 68 axiallyoutwardly or upwardly from locking members 88, 90. Members 88, 90 areprovided with axially extending tabs 88b, 90b, respectively. The springs160, 162 lie in their respective cavities 164', 166' and urge againsttabs 88b, 90b. Springs 160, 162 thereby urge their respective lockingmembers 88, 90 and bolts 96, 98 outwardly into engagement with pockets108 on race 106. As with the second embodiment, the slots 91' in thelocking members 88, 90 of the third embodiment are sufficiently largethat drive pins 92 can be moved from their cap removal positions totheir locking positions, illustrated in FIG. 8, without disturbing theprojection of bolts 96, 98 into respective ones of pockets 108. Thelocations of drive pins 92 in their locking positions allow lockingbolts 96, 98 to move radially inwardly against the urging of springs160, 162. The cooperating surfaces 176, 178 of the bolts and surfaces112' of pockets 108 provide this radial movement to ratchet shell 50 onrace 106. When the drive pins 92 are in their cap removal positionsagainst locking members 88, 90, bolts 96, 98 are held radially outwardlyagainst surfaces 112' to lock shell 50 to race 106 for cap removal(motion in the clockwise direction in FIG. 8).

What is claimed is:
 1. A locking gas cap for a threaded filler neckhaving an axis and sealing lip extending peripherally about said axis,said cap comprising a closure member threaded to engage and close saidfiller neck, gasket means on said closure member for engaging andsealing against said lip, an outer shell providing a hand grip securedto said closure member for rotation thereon about said axis, akey-operated lock and at least one locking member moved by said lock,said lock and locking member being connected to said shell for rotationtherewith, in which the improvement comprises a race disposed forrotation between, and with respect to said shell and closure member,said locking member being movable into and out of engagement with saidrace, said shell and closure member providing adjacent axially facingsurfaces between which said race is axially stationarily positioned, andmeans for drivingly connecting said race and said closure member forrotation together about said axis, said connecting means beingtorque-limited in the direction which advances said closure member onsaid filler neck to protect said gasket means against overtightening andpositive in the opposite direction to permit removal of said cap fromsaid filler neck.
 2. The improvement of claim 1 wherein said means fordrivingly connecting the race and closure member includes at least onedrive finger provided by said closure member, said race being formed toprovide a plurality of peripherally spaced apart pockets, said fingerhaving a distal end portion engageable with said pockets, said fingerbeing resiliently disposed yieldably to urge said distal end portioninto engagement with said pockets, each of said pockets having an abruptleading wall for engaging and driving said finger end portion when saidshell is turned in said opposite direction and an inclined followingwall for engaging and driving said finger end portion when said shell isturned in the first said direction which advances said cap on saidfiller neck, said finger end portion being resiliently urged out of oneof said peripherally spaced apart pockets at the limiting torque.
 3. Theimprovement of claim 1 wherein said locking member is movable into andout of engagement with said race selectively to provide a drivingconnection between said shell and said race.
 4. The improvement of claim1 wherein said locking member is movable into and out of engagement withsaid race, said race being provided with a plurality of radiallyinwardly opening pockets, each of said pockets having an abrupt leadingwall for engaging and driving said locking member when said shell isturned in the first said direction which advances said cap on saidfiller neck, each said pocket further including an inclined followingwall for engaging and driving said locking member when said shell isturned in said opposite direction, said locking member including aninclined wall for engaging the inclined following wall, and an abruptleading wall for engaging said abrupt leading wall of said pocket. 5.The improvement of claim 4 wherein said locking member is spring-urgedinto engagement with said radially inwardly opening pockets.